1. Field of the Invention
The present invention relates to a container and method for manufacture thereof and more particularly to such a container and method which result in a container which obviates the problems associated with conventional containers including the impossibility of examining the contents of such conventional containers without damaging them, the collapsing of palletized stacks of containers while in cold storage, the difficulty in interfitting containers within the stacks thereof and a multiplicity of other problems incident to the manufacture and use of associated with conventional containers.
2. Description of the Prior Art
The use of containers of a variety of types employed in the packing, shipping and storage of fungible goods, and particularly perishable goods such as fresh fruit, fresh vegetables and the like, is compromised by problems inherent in the manufacture and use of such containers. In the packing of perishable goods such as fresh fruit and fresh vegetables, millions of containers of a variety of types are employed each season. The cost of containers must be balanced against their dependability in use and this has resulted in the production and use of containers of a host of different designs and construction materials. Since the containers are disposable, one of the most cost efficient construction materials has been corrugated cardboard or fiberboard. Such containers typically consist of a pair of end panels about which is folded a wrapper whose end portions form top panels or lid portions for the container and are sealed into position using a suitable adhesive. The most common form of adhesive presently in use in the fabrication of conventional containers is known as a "hot melt" adhesive which is applied mechanically. While methods and apparatuses for applying such adhesive work adequately in normal operation, they are subject to a host of difficulties including maintaining the heat of the adhesive at the appropriate temperature, avoiding plugging of the dispensing mechanisms, uneven application and the like.
Such conventional containers may be shipped to the end user, or packer, in flattened blanks and assembled mechanically in the plant just prior to packing, or may be assembled by the box manufacturer leaving the lid portions open for packing and sealing by the packer. In any case, the above noted problems with hot melt adhesives are experienced by the packer in sealing the containers once packed. Such adhesives are normally applied to the side flaps of the lid portions of the container and mechanically folded downwardly into engagement with the side walls as the filled containers are transported along an assembly line. In a sealed container, the juxtaposed marginal edges of the lid portions are typically not adhesively bonded and therefore serve as an entry point for dust, dirt, pests and the like as well as presenting a convenient gripping point for ripping the containers open in unauthorized entry. Furthermore, the strength of the container is compromised by such construction. Upon receipt at the point of destination after shipping, there is no way for the contents of the container to be examined without inflicting permanent damage to the container.
Another problem with containers of this type becomes apparent when the containers are stacked, as is the conventional practice, for storage and shipment. This problem is particularly acute where such containers are stacked in cold storage. The combined weight of the stacked containers causes them individually to collapse under load crushing some or all the contents of the containers and the stack ultimately to lose its integrity. It is not uncommon for palletized stacks to collapse in storage resulting in the substantial or total loss of the contents thereof. The moisture in the humid environment to which such stacks of containers are exposed in cold storage is absorbed by the containers over time causing the corrugated cardboard to lose its rigidity and fail in the manner described. Since typically such prior art containers are formed by folding along score lines, cutting of panels along courses and other such conventional assembly processes, the flutes of the corrugations are frequently crushed, flattened, or otherwise weakened so that the resulting containers are frequently of weakened and irregular configurations, particularly on the folded portions which constitute the load bearing portions of the containers. In stacks of such containers, the irregular load bearing portions, weakened side walls, and the absorption of moisture all contribute to structural failure.
In an effort to enhance the integrity of stacks of such containers, it has been known to use standardized containers having predefined projections which interfit in corresponding slots in adjacent containers to interlock the containers within the stack. However, typically such container construction necessitates that each container individually be lifted into a position of precise registry with the lower container before being rested thereon so that the projections and slots register with each other. However, in actual practice many of the containers are partially or entirely positioned by sliding on the lower container and against the projections. This practice damages the projections and frequently tears the containers. Commonly the containers do not reach the position of registry for which they were designed.
Therefore, it has long been known that it would be desirable to have a container and method for manufacture thereof in which the lid portions are provided with more supporting strength than has heretofore been possible, which permit the contents of a sealed container to be examined without opening or damaging the container, which produce a container having greater vertical strength than is conventionally the case at a cost which is consistent with that of conventional container; which dependably possess the predetermined configuration of their design within substantially closer tolerances, particularly on the load bearing portions thereof; and which have interlocking portions which can be slidably interfitted without damage to the containers or interlocking portions.